MIPS: Implement loop for global regexps in regexp assembler.

src/mips/code-stubs-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5025 matching lines @@
   // a1: previous index
   // a3: encoding of subject string (1 if ASCII, 0 if two_byte);
   // t9: code
   // subject: Subject string
   // regexp_data: RegExp data (FixedArray)
   // All checks done. Now push arguments for native regexp code.
   __ IncrementCounter(isolate->counters()->regexp_entry_native(),
                       1, a0, a2);
 
   // Isolates: note we add an additional parameter here (isolate pointer).
-  const int kRegExpExecuteArguments = 8;
+  const int kRegExpExecuteArguments = 9;
   const int kParameterRegisters = 4;
   __ EnterExitFrame(false, kRegExpExecuteArguments - kParameterRegisters);
 
   // Stack pointer now points to cell where return address is to be written.
   // Arguments are before that on the stack or in registers, meaning we
   // treat the return address as argument 5. Thus every argument after that
   // needs to be shifted back by 1. Since DirectCEntryStub will handle
   // allocating space for the c argument slots, we don't need to calculate
   // that into the argument positions on the stack. This is how the stack will
   // look (sp meaning the value of sp at this moment):
+  // [sp + 5] - Argument 9
   // [sp + 4] - Argument 8
   // [sp + 3] - Argument 7
   // [sp + 2] - Argument 6
   // [sp + 1] - Argument 5
   // [sp + 0] - saved ra
 
-  // Argument 8: Pass current isolate address.
+  // Argument 9: Pass current isolate address.
   // CFunctionArgumentOperand handles MIPS stack argument slots.
   __ li(a0, Operand(ExternalReference::isolate_address()));
+  __ sw(a0, MemOperand(sp, 5 * kPointerSize));
+
+  // Argument 8: Indicate that this is a direct call from JavaScript.
+  __ li(a0, Operand(1));
   __ sw(a0, MemOperand(sp, 4 * kPointerSize));
 
-  // Argument 7: Indicate that this is a direct call from JavaScript.
-  __ li(a0, Operand(1));
-  __ sw(a0, MemOperand(sp, 3 * kPointerSize));
-
-  // Argument 6: Start (high end) of backtracking stack memory area.
+  // Argument 7: Start (high end) of backtracking stack memory area.
   __ li(a0, Operand(address_of_regexp_stack_memory_address));
   __ lw(a0, MemOperand(a0, 0));
   __ li(a2, Operand(address_of_regexp_stack_memory_size));
   __ lw(a2, MemOperand(a2, 0));
   __ addu(a0, a0, a2);
+  __ sw(a0, MemOperand(sp, 3 * kPointerSize));
+
+  // Argument 6: Set the number of capture registers to zero to force global
+  // regexps to behave as non-global.  This does not affect non-global regexps.
+  __ mov(a0, zero_reg);
   __ sw(a0, MemOperand(sp, 2 * kPointerSize));
 
   // Argument 5: static offsets vector buffer.
   __ li(a0, Operand(
         ExternalReference::address_of_static_offsets_vector(isolate)));
   __ sw(a0, MemOperand(sp, 1 * kPointerSize));
 
   // For arguments 4 and 3 get string length, calculate start of string data
   // and calculate the shift of the index (0 for ASCII and 1 for two byte).
   __ Addu(t2, subject, Operand(SeqString::kHeaderSize - kHeapObjectTag));
@@ skipping 30 matching lines @@
   __ LeaveExitFrame(false, no_reg);
 
   // v0: result
   // subject: subject string (callee saved)
   // regexp_data: RegExp data (callee saved)
   // last_match_info_elements: Last match info elements (callee saved)
 
   // Check the result.
 
   Label success;
-  __ Branch(&success, eq, v0, Operand(NativeRegExpMacroAssembler::SUCCESS));
+  __ Branch(&success, eq, v0, Operand(1));
+  // We expect exactly one result since we force the called regexp to behave
+  // as non-global.
   Label failure;
   __ Branch(&failure, eq, v0, Operand(NativeRegExpMacroAssembler::FAILURE));
   // If not exception it can only be retry. Handle that in the runtime system.
   __ Branch(&runtime, ne, v0, Operand(NativeRegExpMacroAssembler::EXCEPTION));
   // Result must now be exception. If there is no pending exception already a
   // stack overflow (on the backtrack stack) was detected in RegExp code but
   // haven't created the exception yet. Handle that in the runtime system.
   // TODO(592): Rerunning the RegExp to get the stack overflow exception.
   __ li(a1, Operand(isolate->factory()->the_hole_value()));
   __ li(a2, Operand(ExternalReference(Isolate::kPendingExceptionAddress,
@@ skipping 2535 matching lines @@
   __ Ret(USE_DELAY_SLOT);
   __ mov(v0, a0);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS